Complement

Question 1

Classic Pathway

Answer 1

IgG or IgM mediated (GM makes classic cars)

Involves C1 and C2 which eventually leads to C3 convertase –> C3a and C3b

Question 2

Alternative Pathway

Answer 2

Mediated by microbe surface molecules

Involves C4 which eventually leads to C3 convertase –> C3a and C3b

Question 3

Lectin Pathway

Answer 3

Mediated by mannose or other sugars on microbe surface

Amplifies the generation of C3b

Question 4

What is the common product of all 3 paths and how does it continue from there?

Answer 4

C3B

C3B –> C5 convertase –> C5a and C5b

C5b joins C6-9 to form MAC complex –> lysis

Question 5

C3b

Answer 5

opsonization (b binds bacteria)

ALONG w/ IgG

Question 6

C3a, C4a, C5a

Answer 6

anaphylaxis

Question 7

C5a

Answer 7

attracts neutrophils

Question 8

DAF

Answer 8

decay accelerating factor or CD55

Helps prevent complement activation of self (like RBCs)

Question 9

C1 esterase inhibitor

Answer 9

also helps prevent complement activation of self

Question 10

C3 deficiency

Answer 10

Inc risk pyogenic sinus and resp infections (PUS)

Inc risk type III hypersensitivity

Question 11

MAC deficiency

Answer 11

Inc risk Neisseria

Question 12

C1 esterase inhibitor deficiency

Answer 12

Hereditary angioedema

Unreg act of kallikrein –> inc bradykinin

Low C4 levels

Do not give ACE inhibitors

Question 13

DAF Deficiency

Answer 13

Complement - mediated lysis of RBCs and paroxysmal nocturnal hemogobinuria